Testing saturation with diffractive jet production in deep inelastic scattering

We analyse the dissociation of a photon in diffractive deep inelastic scattering in the kinematic regime where the diffractive mass is much bigger than the photon virtuality. We consider the dominant q\bar{q}g component keeping track of the transverse momentum of the gluon which can be measured as a final-state jet. We show that the diffractive gluon-jet production cross-section is strongly sensitive to unitarity constraints. In particular, in a model with parton saturation, this cross-section is sensitive to the scale at which unitarity effects become important, the saturation scale. We argue that the measurement of diffractive jets at HERA in the limit of high diffractive mass can provide useful information on the saturation regime of QCD.Comment: 12 pages, 5 figures, misprints corrected, published versio

Saturation effects in forward-forward dijet production in p+Pb collisions

We study saturation effects in the production of forward dijets in proton-lead collisions at the Large Hadron Collider, using the framework of High Energy Factorization. Such configurations, with both jets produced in the forward direction, probe the gluon density of the lead nucleus at small longitudinal momentum fraction, and also limit the phase space for emissions of additional jets. We find significant suppression of the forward dijet azimuthal correlations in proton-lead versus proton-proton collisions, which we attribute to stronger saturation of the gluon density in the nucleus than in the proton. In order to minimize model dependence of our predictions, we use two different extensions of the Balitsky-Kovchegov equation for evolution of the gluon density with sub-leading corrections.Comment: 13 pages, 4 figures; v2: added figure 4, several clarifying sentences and a reference; version accepted by PR

Forward di-jet production in p+Pb collisions in the small-x improved TMD factorization framework

We study the production of forward di-jets in proton-lead and proton-proton collisions at the Large Hadron Collider. Such configurations, with both jets produced in the forward direction, impose a dilute-dense asymmetry which allows to probe the gluon density of the lead or proton target at small longitudinal momentum fractions. Even though the jet momenta are always much bigger than the saturation scale of the target, $Q_s$, the transverse momentum imbalance of the di-jet system may be either also much larger than $Q_s$, or of the order $Q_s$, implying that the small-$x$ QCD dynamics involved is either linear or non-linear, respectively. The small-$x$ improved TMD factorization framework deals with both situation in the same formalism. In the latter case, which corresponds to nearly back-to-back jets, we find that saturation effects induce a significant suppression of the forward di-jet azimuthal correlations in proton-lead versus proton-proton collisions.Comment: 6 figure

Improved TMD factorization for forward dijet production in dilute-dense hadronic collisions

We study forward dijet production in dilute-dense hadronic collisions. By considering the appropriate limits, we show that both the transverse-momentum-dependent (TMD) and the high-energy factorization formulas can be derived from the Color Glass Condensate framework. Respectively, this happens when the transverse momentum imbalance of the dijet system, $k_t$, is of the order of either the saturation scale, or the hard jet momenta, the former being always much smaller than the latter. We propose a new formula for forward dijets that encompasses both situations and is therefore applicable regardless of the magnitude of $k_t$. That involves generalizing the TMD factorization formula for dijet production to the case where the incoming small-$x$ gluon is off-shell. The derivation is performed in two independent ways, using either Feynman diagram techniques, or color-ordered amplitudes.Comment: The improved version of the manuscript. 37 pages, 8 figures, several table

Geology and palaeontology of a temporary exposure of the late Miocene Deurne sand in Antwerpen (N.Belgium)

A section of 6.10 m through the Deurne Sand Member (Diest Formation, Late Miocene) in Antwerpen (Antwerp) is described, which has been observed during the construction works of a new hospital building in the southern part of Deurne, and here called “Middelares Hospital Section” after that location. This temporary outcrop section can well be correlated with a similar one which was outcropping some 35 years ago, and was located at some 1.5 km to the NE. It was studied in detail by De Meuter et al. (1967), who called it the “Borgerhout-Rivierenhof VII B.R.” section. Since that section was the most relevant of the previously described sections in the Deurne Sand Member, it is here suggested to designate that section as stratotype for the member. Part of the fossil content, mainly the macrofossils (Brachiopoda, Mollusca, Ostracoda, Thoracica, Pisces, Reptilia and Mammalia) is listed. Two species of Terebratulidae (Pliothyrina sowerbyana (Nyst, 1843) and Terebratula cf. ampulla Brocchi, 1814) were recognized. The Mollusca are represented by 24 taxa, of which the Pectinidae are the most common. One undescribed ostracod taxon (Thaerocythere sp.) is restricted to the Deurne Sands and can be considered a stratigraphic marker for this member. Fossil Lepadomorpha are recorded for the first time from the Belgian Late Miocene. The Squalus sp. from the Deurne Sands closely resembles the Squalus sp. from the Gramian of Denmark. Preliminary data about a fairly complete skeleton of a Mysticete whale, probably belonging to the genus Plesiocetus Van Beneden (in Van Beneden & Gervais, 1880) are given. The recovered specimen of Ziphirostrum is characteristic of Z. laevigatum and is probably different from Z. belgicus. The molluscan fauna seems to point to a shallow environment with swiftly changing currents, moving sand bars or megaripples subjected to tidal currents. Palaeoclimatological data cannot be deducted from the fossils encountered

Two Weeks of High-Intensity Interval Training in Combination With a Non-thermal Diffuse Ultrasound Device Improves Lipid Profile and Reduces Body Fat Percentage in Overweight Women

This study evaluated the effectiveness of an innovative strategy which combined low-frequency ultra sound (LOFU) with high-intensity interval training (HIIT) to improve physical fitness and promote body fat loss in overweight sedentary women. A placebo controlled, parallel group randomized experimental design was used to investigate the efficacy of a 2-week combined LOFU and HIIT program (3 sessions per week). Participants were allocated into either the Experimental HIIT group (HIITEXP, n = 10) or Placebo HIIT group (HIITPLA, n = 10). Baseline exercise testing (maximal oxygen uptake, lower limb strength and substrate oxidation test), dietary assessment, anthropometric measures and blood sampling were completed in week 1 and repeated in week 4 to determine changes following the program (Post-HIIT). During each training session, the HIITEXP and HIITPLA groups wore a non-thermal diffuse ultrasound belt. However, the belt was only switched on for the HIITEXP group. Delta change scores were calculated for body weight, body fat percentage (Fat%), muscle mass, V.O2max, hip and waist circumferences, and all lipid variables from Baseline to Post-HIIT. Statistical analysis was completed using a repeated-measures factorial analysis of variance by group (HIITPLA and HIITEXP) and time (Baseline and Post-HIIT). Results showed significant improvements in maximal oxygen uptake (HIITEXP; Baseline 24.7 ± 5.4 mL kg–1 min–1, Post-HIIT 28.1 ± 5.5 mL kg–1 min–1 and HIITPLA; Baseline 28.4 ± 5.9 mL kg–1 min–1, Post-HIIT 31.4 ± 5.5 mL kg–1 min–1) for both groups. Significant decreases in Fat% (HIITEXP; Baseline 32.7 ± 3.2%, Post-HIIT 28.9 ± 3.5% and HIITPLA; Baseline 28.9 ± 3.5%, Post-HIIT 28.9 ± 3.4% kg), waist circumference (HIITEXP; Baseline 95.8 ± 9.6 cm, Post-HIIT 89.3 ± 8.9 cm and HIITPLA; Baseline 104.3 ± 3.5 cm, Post-HIIT 103.6 ± 3.4 cm) and triglycerides (HIITEXP; −29.2%, HIITPLA; −6.7%) were observed in the HIITEXP group only. These results show that HIIT combined with LOFU was an effective intervention to improve body composition, lipid profile, and fitness. This combined strategy allowed overweight, sedentary women to achieve positive health outcomes in as little as 2 weeks

A new strategy for faster urinary biomarkers identification by Nano-LC-MALDI-TOF/TOF mass spectrometry

<p>Abstract</p> <p>Background</p> <p>LC-MALDI-TOF/TOF analysis is a potent tool in biomarkers discovery characterized by its high sensitivity and high throughput capacity. However, methods based on MALDI-TOF/TOF for biomarkers discovery still need optimization, in particular to reduce analysis time and to evaluate their reproducibility for peak intensities measurement. The aims of this methodological study were: (i) to optimize and critically evaluate each step of urine biomarker discovery method based on Nano-LC coupled off-line to MALDI-TOF/TOF, taking full advantage of the dual decoupling between Nano-LC, MS and MS/MS to reduce the overall analysis time; (ii) to evaluate the quantitative performance and reproducibility of nano-LC-MALDI analysis in biomarker discovery; and (iii) to evaluate the robustness of biomarkers selection.</p> <p>Results</p> <p>A pool of urine sample spiked at increasing concentrations with a mixture of standard peptides was used as a specimen for biological samples with or without biomarkers. Extraction and nano-LC-MS variabilities were estimated by analyzing in triplicates and hexaplicates, respectively. The stability of chromatographic fractions immobilised with MALDI matrix on MALDI plates was evaluated by successive MS acquisitions after different storage times at different temperatures.</p> <p>Low coefficient of variation (CV%: 10–22%) and high correlation (R²> 0.96) values were obtained for the quantification of the spiked peptides, allowing quantification of these peptides in the low fentomole range, correct group discrimination and selection of "specific" markers using principal component analysis. Excellent peptide integrity and stable signal intensity were found when MALDI plates were stored for periods of up to 2 months at +4°C. This allowed storage of MALDI plates between LC separation and MS acquisition (first decoupling), and between MS and MSMS acquisitions while the selection of inter-group discriminative ions is done (second decoupling). Finally the recording of MSMS spectra to obtain structural information was focused only on discriminative ions in order to minimize analysis time.</p> <p>Conclusion</p> <p>Contrary to other classical approaches with direct online coupling of chromatographic separation and on the flight MS and/or MSMS data acquisition for all detected analytes, our dual decoupling strategy allowed us to focus on the most discriminative analytes, giving us more time to acquire more replicates of the same urine samples thus increasing detection sensitivity and mass precision.</p

L-Lactate protects neurons against excitotoxicity: implication of an ATP-mediated signaling cascade.

Converging experimental data indicate a neuroprotective action of L-Lactate. Using Digital Holographic Microscopy, we observe that transient application of glutamate (100 μM; 2 min) elicits a NMDA-dependent death in 65% of mouse cortical neurons in culture. In the presence of L-Lactate (or Pyruvate), the percentage of neuronal death decreases to 32%. UK5099, a blocker of the Mitochondrial Pyruvate Carrier, fully prevents L-Lactate-mediated neuroprotection. In addition, L-Lactate-induced neuroprotection is not only inhibited by probenicid and carbenoxolone, two blockers of ATP channel pannexins, but also abolished by apyrase, an enzyme degrading ATP, suggesting that ATP produced by the Lactate/Pyruvate pathway is released to act on purinergic receptors in an autocrine/paracrine manner. Finally, pharmacological approaches support the involvement of the P2Y receptors associated to the PI3-kinase pathway, leading to activation of KATP channels. This set of results indicates that L-Lactate acts as a signalling molecule for neuroprotection against excitotoxicity through coordinated cellular pathways involving ATP production, release and activation of a P2Y/KATP cascade